1809 description of how to solder fine instruments

[Chris Treichel]

section 1776-1780 The Philosophical Transactions of the Royal Society printed 1809... pg 177... instrument makers... Having cleaned the parts to be soldered very well cut out a piece of tin foil the exact size of them then dip a feather into a pretty strong solution of sal ammoniac in water and rub it over the surfaces to be soldered after which place the tin foil between them as fast as you can for the air will quickly corrode their surfaces so as to prevent the solder taking and give the whole a gradual and sufficient heat to melt the tin If the joints to be soldered have been made very flat they will not be thicker than a hair though the surfaces be ever so extensive the soldering may be conducted in the same manner only care must be taken by general pressure to keep them close together In this manner for instance a silver graduated plate may be soldered on to the brass limb of a quadrant so as not to be discernible by any thing but the different colour of the metals This method was communicated to me by the late Mr Jackson who during his life kept it a secret as he used it in the construction of his quadrants and is I believe not as yet known to any workman.

[Mike C]

Is sal ammoniac what we know as ammonia??
Mike C

[Robby]

http://en.wikipedia.org/wiki/Sal_ammoniac

[WadePatton]

Is sal ammoniac what we know as ammonia??
Mike C

nope.

wiki:

It is commonly used to clean the soldering iron in the soldering of stained-glass windows. In both jewellery-making and the refining of precious metals, potassium carbonate is added to gold and silver in a borax-coated crucible to purify iron or steel filings that may have contaminated the scrap. It is then air-cooled and remelted with a one-to-one mixture of powdered charcoal and sal ammoniac to yield a sturdy ingot of the respective metal or alloy in the case of sterling silver (7.5% copper) or karated gold.

Sal ammoniac has also been used in the past in bakery products to give cookies a very crisp texture, although that application is rapidly dying due to the general disuse of it as an ingredient. However, in some areas of Europe, particularly Nordic countries and the Netherlands, it is still widely used in the production of salty licorice candy known as Salmiak or Salmiakki.[7]

Sal Ammoniac (ammonium chloride) was the electrolyte in Leclanche cells, a forerunner of the dry battery—where a carbon rod and a zinc rod or cylinder formed the electrodes.

Sal ammoniac is a rare mineral composed of ammonium chloride, NH4Cl. It forms colorless to white to yellow-brown crystals in the isometric-hexoctahedral class. It has very poor cleavage and a brittle to conchoidal fracture.




http://en.wikipedia.org/wiki/Sal_ammoniac



Somewhere i saw (saved i'm sure) a listing of all those "olde" chemical names and a/k/a's with their modern names-because all that changed back between then and now.  Much of it anyway.  Clyde Baker's 1935 book on gunsmithing uses the old names...that's where i first ran into mysterious chemicals and compounds.  Bad news is you can't acquire them locally anymore, good news is that Ebay/Amazon/et al has plenty.

The last thing you want to do is try to make "sounds alike" guesses with this stuff.  That could turn very nasty pronto and schneller! 

[Mad Monk]

Wade,

Some of the industrial chemistry books from the early 1900's are funny on this kind of stuff.

Salamoniac, or ammonium chloride, once came only from China.  Way back in time.  It was claimed that it was found as "snow" on the top of a high mountain in China.

Ammonium chloride has also seen long use as an expectorant in treating cold coughs.

The older industrial chemistry books list ammonium chloride as a "manure salt".  That is actually where most of it came from into the early 1900's.

You see modifications of it in a lot of present day sanitizing products sold to the public.  With claims that the modified form will kill 99% of bacteria.  I find that claim questionable.  Ammonia chloride was a product of manure pile manipulation.  With a wide variety of other bacteria at work in the manure.  So why didn't the production of this ammonium chloride  by several varieties of bacteria kill off other bacteria in the manure pile.

I have long used a 5% solution of ammonium chloride to brown ML barrels.  It only takes about 4 hours for an application to go to completion.  For a few years I did janitorial work in the evening hours.  I refused you use any of the ammonium chloride based cleaners on any of the stainless steel in the office lunch rooms or rest rooms.  Does really ugly things to stainless steels.

Mad Monk

[David R. Pennington]

I still use sal ammoniac to "fix" my soldering irons. I am almost out. I used to bum a piece or two from the local sheet metal shop but last time I tried they didn't have any. I found it at McMaster Carr (industrial supply) they have it on their web site. They also list a case hardening compound that appears reasonable but I haven't tried it yet.

[Chris Treichel]

This might be of interest too...  Chemical Essays by Richard Watson 1788
Chemical Essays link

[Sawatis]

Any shop that sells stained glass supplies will have blocks of it about 2.5 inch cubes.  Not hard to get my wife uses it on her irons etc all the time.
John

[FALout]

As already stated, sal ammonia can can be purchased at most stain glass supply business's, very commonly used for cleaning the tips of soldering irons.  I'd be careful of breathing any of this stuff when tinning your parts, I know that you don't want to get on your skin.  Very cheap, usually about $4-5 for a block of the stuff, not sure about solubility in water.